org.springframework.data.mapping.PreferredConstructor Java Examples

private <ET> ET instantiate(Neo4jPersistentEntity<ET> nodeDescription,
	MapAccessor values,
	KnownObjects knownObjects,
	Collection<RelationshipDescription> relationships,
	Collection<String> surplusLabels) {

	ParameterValueProvider<Neo4jPersistentProperty> parameterValueProvider = new ParameterValueProvider<Neo4jPersistentProperty>() {
		@Override
		public Object getParameterValue(PreferredConstructor.Parameter parameter) {

			Neo4jPersistentProperty matchingProperty = nodeDescription
				.getRequiredPersistentProperty(parameter.getName());

			if (matchingProperty.isRelationship()) {
				return createInstanceOfRelationships(matchingProperty, values, knownObjects, relationships)
					.orElse(null);
			} else if (matchingProperty.isDynamicLabels()) {
				return createDynamicLabelsProperty(matchingProperty.getTypeInformation(), surplusLabels);
			}
			return readValueForProperty(extractValueOf(matchingProperty, values), parameter.getType());
		}
	};

	return INSTANTIATORS.getInstantiatorFor(nodeDescription)
		.createInstance(nodeDescription, parameterValueProvider);
}
 

private ConstructorExpression<?> getConstructorExpression(Class<?> type, RelationalPath<?> pathBase) {
    PreferredConstructor<?, ?> constructor = PreferredConstructorDiscoverer.discover(type);

    if (constructor == null) {
        throw new IllegalArgumentException(
                "Could not discover preferred constructor for " + type);
    }

    Map<String, Path<?>> columnNameToColumn = pathBase.getColumns()
                                                      .stream()
                                                      .collect(Collectors.toMap(
                                                              column -> column.getMetadata().getName(),
                                                              Function.identity()));

    Path<?>[] paths = constructor.getParameters()
                                 .stream()
                                 .map(PreferredConstructor.Parameter::getName)
                                 .map(columnNameToColumn::get)
                                 .toArray(Path[]::new);

    return Projections.constructor(type, paths);
}
 

private boolean shouldSkipProperty(StructAccessor struct,
		SpannerPersistentProperty spannerPersistentProperty,
		Set<String> includeColumns,
		boolean readAllColumns,
		boolean allowMissingColumns,
		PreferredConstructor<?, SpannerPersistentProperty> persistenceConstructor) {
	String columnName = spannerPersistentProperty.getColumnName();
	boolean notRequiredByPartialRead = !readAllColumns && !includeColumns.contains(columnName);


	return spannerPersistentProperty.isLazyInterleaved() ||
			notRequiredByPartialRead
			|| isMissingColumn(struct, allowMissingColumns, columnName)
			|| struct.isNull(columnName)
			|| persistenceConstructor.isConstructorParameter(spannerPersistentProperty);
}
 

@Override
public <T> T getParameterValue(PreferredConstructor.Parameter<T, RelationalPersistentProperty> parameter) {
    RelationalPersistentProperty property = entity.getRequiredPersistentProperty(parameter.getName());
    Object value = row.getValue(property.getColumnName());
    Class<T> type = parameter.getRawType();

    return convertIfNecessary(value, type);
}
 

/**
 * Reads a single POJO from a Cloud Spanner row.
 * @param type the type of POJO
 * @param source the Cloud Spanner row
 * @param includeColumns the columns to read. If null then all columns will be read.
 * @param allowMissingColumns if true, then properties with no corresponding column are
 * not mapped. If false, then an exception is thrown.
 * @param <R> the type of the POJO.
 * @return the POJO
 */
@SuppressWarnings("unchecked")
public <R> R read(Class<R> type, Struct source, Set<String> includeColumns,
		boolean allowMissingColumns) {
	boolean readAllColumns = includeColumns == null;
	SpannerPersistentEntity<R> persistentEntity =
			(SpannerPersistentEntity<R>) this.spannerMappingContext.getPersistentEntity(type);

	StructAccessor structAccessor = new StructAccessor(source);

	StructPropertyValueProvider propertyValueProvider = new StructPropertyValueProvider(
			structAccessor,
			this.converter,
			this, allowMissingColumns);

	PreferredConstructor<?, SpannerPersistentProperty> persistenceConstructor = persistentEntity
			.getPersistenceConstructor();

	// @formatter:off
	ParameterValueProvider<SpannerPersistentProperty> parameterValueProvider =
					new PersistentEntityParameterValueProvider<>(persistentEntity, propertyValueProvider, null);
	// @formatter:on

	EntityInstantiator instantiator = this.instantiators.getInstantiatorFor(persistentEntity);
	R instance = instantiator.createInstance(persistentEntity, parameterValueProvider);
	PersistentPropertyAccessor accessor = persistentEntity.getPropertyAccessor(instance);

	persistentEntity.doWithProperties(
			(PropertyHandler<SpannerPersistentProperty>) (spannerPersistentProperty) -> {
				if (spannerPersistentProperty.isEmbedded()) {
					accessor.setProperty(spannerPersistentProperty,
							read(spannerPersistentProperty.getType(), source,
									includeColumns, allowMissingColumns));
				}
				else {
					if (!shouldSkipProperty(structAccessor, spannerPersistentProperty,
							includeColumns, readAllColumns, allowMissingColumns,
							persistenceConstructor)) {

						Object value = propertyValueProvider
								.getPropertyValue(spannerPersistentProperty);
						accessor.setProperty(spannerPersistentProperty, value);
					}
				}
			});

	return instance;
}
 

/**
 * Typical code used to read entities in {@link org.springframework.data.convert.EntityReader}.
 *
 * @param data
 * @param classToRead
 * @param queryCustomConversions {@literal true} to call {@link CustomConversions#hasCustomReadTarget(Class, Class)}.
 * @return
 */
@SuppressWarnings("unchecked")
private Object read(Map<String, Object> data, Class<?> classToRead, boolean queryCustomConversions) {

	if (queryCustomConversions) {
		customConversions.hasCustomReadTarget(Map.class, classToRead);
	}

	MyPersistentEntity<?> persistentEntity = context.getRequiredPersistentEntity(classToRead);
	PreferredConstructor<?, MyPersistentProperty> constructor = persistentEntity.getPersistenceConstructor();

	ParameterValueProvider<MyPersistentProperty> provider = constructor.isNoArgConstructor() //
			? NONE //
			: new ParameterValueProvider<MyPersistentProperty>() {

				@Override
				public <T> T getParameterValue(Parameter<T, MyPersistentProperty> parameter) {
					return (T) getValue(data, parameter.getName(), parameter.getType().getType(), queryCustomConversions);
				}
			};

	EntityInstantiator instantiator = instantiators.getInstantiatorFor(persistentEntity);
	Object instance = instantiator.createInstance(persistentEntity, provider);

	if (!persistentEntity.requiresPropertyPopulation()) {
		return instance;
	}

	PropertyValueProvider<MyPersistentProperty> valueProvider = new PropertyValueProvider<MyPersistentProperty>() {

		@Override
		public <T> T getPropertyValue(MyPersistentProperty property) {
			return (T) getValue(data, property.getName(), property.getType(), queryCustomConversions);
		}
	};

	PersistentPropertyAccessor<?> accessor = new ConvertingPropertyAccessor<>(
			persistentEntity.getPropertyAccessor(instance), conversionService);

	readProperties(data, persistentEntity, valueProvider, accessor);

	return accessor.getBean();
}